Dictionary » C » C4 carbon fixation pathway

C4 carbon fixation pathway

Definition

noun

A metabolic pathway where CO2 is first added to phosphoenolpyruvate by the enzyme, PEP carboxylase, producing the four-carbon compound within mesophyll cells that is later transported to the bundle sheath cells where the CO2 is to be released for use in the Calvin cycle.


Supplement

Instead of the direct carbon fixation in the Calvin cycle like in C3 carbon fixation, the C4 pathway involves steps that first converts pyruvate to phosphoenolpyruvate (PEP) to bind with the CO2 forming a four-carbon compound (hence the name C4). As a result, the photorespiration pathway is bypassed, and the wasteful loss of CO2 common in C3 carbon fixation pathway is minimized.

Plants that first go through the C4 pathway are better adapted than plants that solely go through the C3 pathway under conditions of drought, high temperatures and low nitrogen or CO2 concentrations.


Word origin: from the intermediate organic compound, which contains four carbon atoms, hence the name C4.

Synonym: hatch slack kortshak pathway, Hatch-Slack pathway.
Compare: C3 carbon fixation pathway, Crassulacean acid metabolism.
See also: C4 plant.


Please contribute to this project, if you have more information about this term feel free to edit this page



Results from our forum


Photosynthesis Trivia

... for photosynthesis produces (A.) water and carbon dioxide (B.) water and oxygen (C.) carbohydrate ... fresh water (D.) the oceans 8. The Hatch-Slack pathway is (A.) another name for the Calvin Cycle ... (D.) carbon dioxide (E.) none of these 13. The fixation of carbon dioxide into energy rich ...

See entire post
by vstexas09
Mon Oct 13, 2008 12:46 am
 
Forum: Cell Biology
Topic: Photosynthesis Trivia
Replies: 5
Views: 30459

carbon fixation of conifers

What carbon fixation pathway do conifers use? Is it CAM? I haven't found an explicit answer yet. ...

See entire post
by dae
Sat Aug 09, 2008 9:37 pm
 
Forum: Botany Discussion
Topic: carbon fixation of conifers
Replies: 2
Views: 3177

Re: carbon fixation reactions

so can either the c3 or c4 pathway work at night too? or just day?

See entire post
by sar1828
Mon Mar 10, 2008 10:44 pm
 
Forum: Botany Discussion
Topic: carbon fixation reactions
Replies: 3
Views: 4073

carbon fixation reactions

So I know that the CAM pathway takes place during night and day, and the calvin cycle in the CAM pathway takes place during the day- but what about C3 and C4 pathways, they both have a calvin cycle does it take place during the day too? ...

See entire post
by sar1828
Mon Mar 10, 2008 5:53 am
 
Forum: Botany Discussion
Topic: carbon fixation reactions
Replies: 3
Views: 4073

Cellular respiration in sperm cells.

... with respect to the product of photosynthetic carbon fixation during the Calvin cycle. During plant photosynthesis, ... Glycolysis pathway. The color scheme is as follows: enzymes, coenzymes, ...

See entire post
by baikuza
Wed Feb 15, 2006 7:47 am
 
Forum: Cell Biology
Topic: Cellular respiration in sperm cells.
Replies: 15
Views: 15535
View all matching forum results

This page was last modified 10:23, 29 August 2008. This page has been accessed 25,469 times. 
What links here | Related changes | Permanent link